Really tough string, as always from D'Addario. I play fairly heavily and batter my strings and these always last me ages. They remain sounding punchy and clear throughout their lifespan regardless of the tuning they're in or what kind of sound I'm using at the time. D'Addario's range of single strings are great for building custom sets for alternate tunings, as I often do. It allows me to get the perfectly balanced tension for whatever tuning I'm using at the time to produce the best sound and feel for what I'm after, more so than any other brand in my experience over the years.